What the Options in the Bedrock Custom Super Flat Generator Mean

Updated

The Bedrock Custom Super Flat Generator is a web form that builds a custom flat world for Minecraft Bedrock. Its options fall into three groups: World Type (Custom Super Flat or Single Biome), world identity fields (World Name, Seed, Biome), and the Prevent Slimes Spawning toggle. You pick a type, fill in the fields that type exposes, optionally block slimes, and then generate the world. The exact output format and how you load it into the game are not described on the page, so treat the form as the input step and confirm the resulting file against your own Bedrock setup.

World Type: the first decision

The page opens with a -- Select World Type -- dropdown containing two choices. This selection changes which of the other fields matter.

World Type What it controls Fields that apply
Custom Super Flat A flat world whose layers you define yourself World Name, Seed, Prevent Slimes Spawning
Single Biome A flat world locked to one biome World Name, Seed, Biome, Prevent Slimes Spawning

Choose Custom Super Flat when the point of the world is the layer stack — a build platform, a redstone test bed, a void-style base. Choose Single Biome when the point is consistent scenery or resources across the whole map, such as an all-desert or all-snow world.

The world identity fields

World Name

A label for the world. Use something you will recognise later when the world appears in your Minecraft world list, especially if you generate several test worlds. Keep it short and avoid characters your device's file system rejects.

Seed

The number or text string that determines world generation. For a superflat world the visible terrain is mostly your chosen layers, so the seed matters less for the surface and more for anything the game still derives from it. If you want two worlds to match, reuse the same seed; if you want variation, change it.

Biome

This field only does something useful when Single Biome is selected. It sets the biome applied across the flat world, which affects sky colour, weather behaviour, mob spawning rules, and which plants or structures can appear. Leave it alone for Custom Super Flat unless you specifically want a biome override.

Prevent Slimes Spawning

A checkbox that suppresses slime spawning in the generated world. Slimes spawn in slime chunks and in swamp biomes, and on a flat world with open space they can become a nuisance in farms, storage rooms, and redstone builds. Tick it when you want a clean, predictable world; leave it unticked if you are deliberately building a slime farm or testing slime mechanics.

A practical order of operations

  1. Select Custom Super Flat or Single Biome from the World Type dropdown.
  2. Enter a World Name you will recognise.
  3. Enter a Seed — reuse an existing one if you want a matching world.
  4. If you chose Single Biome, set the Biome.
  5. Tick Prevent Slimes Spawning if slimes would interfere with your build.
  6. Press Generate to produce the world.

Common sticking points

  • Biome seems ignored. It only applies to Single Biome; on Custom Super Flat the field has no visible effect.
  • Slimes still appear. The toggle is a setting on the generated world, so check it was ticked before you pressed Generate rather than after.
  • Two worlds don't match. Compare both the seed and the world type — a Single Biome world and a Custom Super Flat world with the same seed are not the same world.
  • Not sure what you get back. The page does not spell out the download or import step, so after generating, check what file or code the site gives you and follow your platform's usual route for adding a world to Bedrock.